Where's the fuel screw in this photo
- Thread starter Elkhorn1
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Its not an "EDIC idle stop".. its the pump's "run" position... and the pump's default run position is "max fuel".
The large screw is indeed the fuel control screw.. when the engine starts and the throttle butterfly is shut there's max vacuum from beneath the butterfly and the rack moves back to the idle position.. when the throttle is wide open there's no vacuum and the rack position is set by the fuel control arm.. that screw is what determines the max fuel position.
To increase max fuel wind the screw back towards the firewall (ie wind it out).. to decrease fuel wind the screw in. (towards the radiator).. A 1/4 of a turn at a time between tests is about right.. take the vehicle for a drive up a hill and put it under load.. you're looking for just a bit of smoke (depending on how good of a condition your injectors and air filter are in).. ultimately getting the vehicle on a dyno will allow it to be set correctly..
I'm by no means an expert on either pump.. I have never worked on a B series pump. I am guessing that by the look of that bolt on yours it's not the original part..
Hopefully you also have a pyro gauge to ensure you're not driving it too hard..
The same screw exists on the 2H.. they are very similar pumps.. here's a picture I previously posted for the 2H screw (remembering also that its on the other side of the engine compared to a B series engine..
The large screw is indeed the fuel control screw.. when the engine starts and the throttle butterfly is shut there's max vacuum from beneath the butterfly and the rack moves back to the idle position.. when the throttle is wide open there's no vacuum and the rack position is set by the fuel control arm.. that screw is what determines the max fuel position.
To increase max fuel wind the screw back towards the firewall (ie wind it out).. to decrease fuel wind the screw in. (towards the radiator).. A 1/4 of a turn at a time between tests is about right.. take the vehicle for a drive up a hill and put it under load.. you're looking for just a bit of smoke (depending on how good of a condition your injectors and air filter are in).. ultimately getting the vehicle on a dyno will allow it to be set correctly..
I'm by no means an expert on either pump.. I have never worked on a B series pump. I am guessing that by the look of that bolt on yours it's not the original part..
Hopefully you also have a pyro gauge to ensure you're not driving it too hard..
The same screw exists on the 2H.. they are very similar pumps.. here's a picture I previously posted for the 2H screw (remembering also that its on the other side of the engine compared to a B series engine..
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- Thread starter
- #3
Thank you so much. All the photos I had seen had the screw and lock nut mounted in an "ear" of the pump body rather than on an external bracket like mine. I assumed that the screw physically metered fuel in an orifice, rather than setting the position of the tab ( the one connected to the edic arm and labelled "stop" on top)
When I couldn't find a hole for safety wire I was confused, but obviously it's just been replaced. I'll look closely at lunchtime, but your explanation makes sense.
I'm actually looking to turn down fuel a little to try and find the sweet spot where it is driveable but I don't have to warn my wife to watch the EGTs because she will not enjoy gazing admiringly at the EGT and Boost gauges like I do.
When I couldn't find a hole for safety wire I was confused, but obviously it's just been replaced. I'll look closely at lunchtime, but your explanation makes sense.
I'm actually looking to turn down fuel a little to try and find the sweet spot where it is driveable but I don't have to warn my wife to watch the EGTs because she will not enjoy gazing admiringly at the EGT and Boost gauges like I do.
Check out the photo in this post.. looks like there's sometimes other kit thats mounted on that tab maybe some kind of boost or high altitude compensator.. either way, its definitely the right screw. I bet yours had that additional kit at some point.
https://forum.ih8mud.com/threads/trying-to-find-correct-3b-block-heater.649588/#post-8071811
I too like looking at gauges admiringly
https://forum.ih8mud.com/threads/trying-to-find-correct-3b-block-heater.649588/#post-8071811
I too like looking at gauges admiringly
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